Art of electbotyping



Feb a E. VOIGT ART OF ELECTROTYPING Filed Feb. 19, 1923 Mmmm Patented Feb. 12, 1924.

UNITED STATES EDMUND VOIGT, OF CHICAGO, ILLINOIS.

ART or nnnoraorxrme.

Application med february19,-1923. Serial No. 619,936.

T o' all whom it may concern? Be it known that I, EDMUND Yoro'r, a citi- -zen of the United States, residlng at Chicago, in'the county of Cook and State of Illinois, have invented a new and useful Improvement in the Art of Electrotyping, of which the following is a specification.

My 'invention relates to an improved method of preparing the plate, on which the electrotype-shell is to be produced by electrodeposition, for immersion in the electrolyte.. Y 4 Common practice, as known tome, for the aforesaid purpose involves supporting 1 the metal plate or matrix on a case of metal covered with a film of wax, or other electrically insulating material, and which is provided with holes near itsupper end to receive horn-like hangers on the so-called hook,. through the medium of which the late is suspended, as shown in my Patent o. 1,412,909, dated April 18, 1922, in a tank-containing electrolyte and the electric current is directed to the work; and the plate 2 is usually stopped off, or covered with wax, to expose to electrodeposition only so much of the surface thereof as is to be reproduced by the shell-formation. This practice is excessively wasteful, not

' only of electricity because the entire matrix conducts the current and therefore supplies it excessively, but the deposited shell-forming metal adheres so tightly to the face of the matrix that its removal is attended with 95 .difiiculty and not infrequently with such im-.

airment and even destruction as to require 1t to be discarded and the work to? be performed over again, and this sometimes repeatedly.

. My improvement entirel overcomes the objections referred to in t e elee trotyping practice, by preparing the matrix inthe manner hereinafter described with reference to the accompanying drawing, in whith- Figure 1 shows a face view of the matrix prepared in accordance with my improve-- ment; Figure 2 is an edge-view showing how the plate is suspended on the hook, of which only the lower portion is represented, and Figure 3 is a broken section on line 3, Fig. ,1, but in exaggerated representation to illus trate the procedure in practising myimprovement, for-clearly indicating Wl'llCl'l in Fig. 2 the edge-vie'w-presented is unsuited. The case 4, which is usually a metallic amount of current.

sheet coated with wax to insulate. it, but

which I prefer to provide in its entirety of insulating material, such as gutta-percha, is shown to be provided with holes 5 near its upper edge for suspending it on the hook 6 00 (Fig. 2) at horn-shaped hangers 7 on the lower end thereof. The hook may be that of my aforesaid patent, or may be of ordinary, or any desired construction, and is provided with apivotal metal shoev 9represented to be under pressure of a s ring 10 secured at 11 toa side of the lower ook-end.

The matrix 12, of copper, lead or other suitable metal, and bearing the configuration, such as that shown at 13 (Fig. 1), to

'be .electrotyped, and which is secured to the face of the sheet 4, preferably by cementation with wax, is prepared for my purpose, for suspension in the electrolyte, as follows:

I coat the surface with a thin film 14c of suitable insulating material, such as shellac, and secure on the face of the plate in the preferred position represented, thus centrally near its upper end, as by cementing it in place by the shellac coating, or by wax if desired, a metal contact-strip 15. 'The entire face of the matrix is thereupon coated with a suitable electro-conductive substance 16, preferably plumbago, which may be readily dusted thereon and may, though not necessarily, also cover the strip 15; and the face may thereupon be stepped off, as it is called in the art, about the configuration, for which purpose wax, represented at 17, is ordinarily used.

With the matrix, thus prepared, suspended as usual in an electrolyte-containing tank, and the shoe 9 in close contact with the strip 15, the flow of electric current used is confined to the conducting sur- 95 face 16 and effects the electrolytic-al deposit pf the shell, which is represented at 18 in The electrotype shell thus produced may be readily stripped off the matrix without 2 impairment, thereby avoiding 'all need 0 repeating the work and resultant waste; and the flow-of'electricity being confined to the imposed conducting surface 16, the work may be performed with the minimum 105 The stop-off wax 17 shown in Fig. 1 of the drawing to extend over the surface of the matrix 12 between the lower edge of the contact-strip 15 and the configuration 13, be omitted from that portion of the surface to prevent tendency of the act of there applying it to remove the plumbago therefrom, or disturb its continuity and thus impair the conductivity of the plumbago coating.

I realize that considerable variation is possible in practising the improved method herein specifically described and I do not intend to limit my invention thereto except as pointed out in the appended claims, in which it is my intention to claim all the novelty inherent in my invention as broadly as permissible by the state of the art.

I claim:

1. The method of preparing a matrix for electrodeposition thereon of an electrotypeshell, which comprises providing the outer surface of the matrix with an electro-conductive surface electrically insulated from the matrix-surface.

v2. The method of preparing a matrix for electrodeposition thereon of an electrotypeshell, which comprisesproviding the outer surface of the matrix with an insulating film and providing an electro-conductive curface on said film to carry the flow of electric current.

3. The method of preparing a matrix for electrodeposition thereon of an electrotypeshell, which comprises coating the outer surface of the matrix with a film of insulating material, applying to the coated matrix an electrical-contact strip, and coating the insulated surface with electro-conductive' material.

4; The method of preparing a matrix for electrodeposition thereon of an electrotypeshell, which comprises coating the outer surface of the matrix with a film of insulating material, applying to the coated matrix an electrical-contact strip, coating the insulated surface with electro-conductive material, and stopping 0d the matrix.

5. The method of preparing a matrix for electrodeposition thereon of an electrotypetype-shell, which comprises coating the outer surface of the matrix with a film of shellac, securing on the coated surface an' electrical-contact strip, and coating the shellac-surface with plumbago.

' EDMUND VOIGT. 

